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From:   Shakeel Butt <shakeelb@google.com>
Date:   Mon, 13 Sep 2021 21:32:25 -0700
Message-ID: <CALvZod7Y4pC4XvqVp+tJ==CnS5Ay8YPqrxeUzA8tMLu+0U3hjQ@mail.gmail.com>
Subject: Re: [PATCH] ipc: remove memcg accounting for sops objects in do_semtimedop()
To:     Michal Hocko <mhocko@suse.com>
Cc:     Vasily Averin <vvs@virtuozzo.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Johannes Weiner <hannes@cmpxchg.org>, kernel@openvz.org,
        Cgroups <cgroups@vger.kernel.org>
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On Mon, Sep 13, 2021 at 1:37 AM Michal Hocko <mhocko@suse.com> wrote:
>
[...]
> > However Shakeel Butt pointed that there are much more popular objects
> > with the same life time and similar memory consumption, the accounting
> > of which was decided to be rejected for performance reasons.
>
> Is there any measurable performance impact in this particular case?
>

I don't think there was any regression report or any performance
evaluation. Linus raised the concern on the potential performance
impact. I suggested to backoff for this allocation for now and revisit
again once we have improved the memcg accounting for kernel memory.